Molluscum contagiosum pathophysiology

Revision as of 18:46, 21 September 2017 by Mmir (talk | contribs) (Category)
Jump to navigation Jump to search

Molluscum contagiosum Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Molluscum contagiosum from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic criteria

History and Symptoms

Physical Examination

Laboratory Findings

X ray

Ultrasound

CT Scan

MRI

Other Imaging Studies

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Mahshid Mir, M.D. [2]

Overview

Molluscum contagiosum is usually transmitted via direct contact with a skin lesion. Following transmission, molluscum contagiosum uses the human cell machinery to replicate. On gross pathology, a central umbilication and punctiform vessels are characteristic findings of molluscum contagiosum. On electron microscopic analysis, typical brick-shaped poxvirus particles inside the infected tissue are characteristic findings of molluscum contagiosum.

Pathogenesis

  • The human molluscum contagiosum virus (MCV) is a DNA poxvirus.
  • MCV has no animal reservoir, infecting only humans.
  • MCV replicates in cells cytoplasm. This may be related to genetic similarity in variola and vaccinia viruses more than one-half.
  • In adults, molluscum infections are often sexually transmitted and usually affect the genitals, lower abdomen, buttocks, and inner thighs. In rare cases, molluscum contagiosum infections are also found on the lips, mouth, and eyelids. It spread through direct contact or shared articles of clothing (including towels).
  • MCV can commonly cause asymptomatic cutaneous neoplasms. Children and sexually active adults as well as persistent opportunistic acquired immunodeficiency syndrome (AIDS)-associated disease are more sensitive to the virus and more in danger for cutaneous neoplasm. [1]

Genetics

  • In 1997, Senkevich et al were the first who described molluscum contagiosum virus (MCV) genome.[2]
  • MCV possesses 59 genes predicted to code for novel proteins including MHC-class I, chemokine, and glutathione peroxidase homologs not found in other poxviruses. The MCV genomic data is near complete which can allow the investigation of host defense mechanisms. These information also can provide new possibilities for the development of therapeutics for treatment and prevention of the MCV infection.[3][4]
  • Molluscum contagiosum inhibits the host inflammatory response. This unique feature seems to be related to some of the specific genes that are present in its genome.
  • Scientists have sequenced more than 190-kilobase pair genome of MCV. These genome findings have revealed that the virus potentially encodes approximately 182 proteins, 105 of which have direct counterparts in orthopoxviruses (OPV).[1] Another study suggests that MCV lacks counterparts to 83 genes of the smallpox virus, including those important in suppression of host responses to infection, nucleotide biosynthesis, and cell proliferation.[3]

Gross Pathology

In a dermoscopic exam of infected tissue the important parts include:

  • A central umbilication with polylobular, white to yellow amorphous structures
  • A peripheral crown of radiating or punctiform vessels[4]

Microscopic Pathology

Electron microscopic evaluation of tissue is not a part of routine diagnosis procedure, but if done it may show:[4]

References

  1. 1.0 1.1 Fife KH, Whitfeld M, Faust H, Goheen MP, Bryan J, Brown DR (1996). "Growth of molluscum contagiosum virus in a human foreskin xenograft model". Virology. 226 (1): 95–101. doi:10.1006/viro.1996.0631. PMID 8941326.
  2. Senkevich TG, Koonin EV, Bugert JJ, Darai G, Moss B (1997). "The genome of molluscum contagiosum virus: analysis and comparison with other poxviruses". Virology. 233 (1): 19–42. doi:10.1006/viro.1997.8607. PMID 9201214.
  3. 3.0 3.1 Bugert JJ, Darai G (1997). "Recent advances in molluscum contagiosum virus research". Arch. Virol. Suppl. 13: 35–47. PMID 9413524.
  4. 4.0 4.1 4.2 Senkevich TG, Koonin EV, Bugert JJ, Darai G, Moss B (1997). "The genome of molluscum contagiosum virus: analysis and comparison with other poxviruses". Virology. 233 (1): 19–42. doi:10.1006/viro.1997.8607. PMID 9201214.

Template:WikiDoc Sources